<!DOCTYPE html>
<html lang="en">
  <head>
    <meta charset="UTF-8" />
    <meta name="viewport" content="width=device-width, initial-scale=1.0" />
    <title>发光羽毛球</title>
    <style>
      body {
        background-color: #000;
      }

      .badminton {
        width: 100px;
        height: 100px;
        background-image: radial-gradient(#ffff00 10%, transparent 60%, transparent);
      }
    </style>
  </head>
  <body>
    <div class="badminton"></div>
  </body>
</html>
